Figure 8.

Model depicting the differential interaction of NFY with the α1 collagen promoter in which it serves only as a constitutive activator, and with the CHOP promoter in which it is required not only for constitutive activation but also ER-stress inducibility. It is proposed that the ER-stress inducible ‘i’ domain locates right to a DNA region in which NFY makes contact. Both the specific sequence of the ‘i’ domain and the region of NFY that makes contact with such a domain contribute to the creation of a new interaction surface for a putative ERSF, equivalent to the yeast Hac1p.